HomeMy WebLinkAboutCC - Storm Drainage Calcs Lennon Pointe
Subdivision
1515 W Ustick Road
Meridian, Idaho 83646
WESTERN CONSULTING
GROUP
Stormwater Management
Report
Owner:
Mr. Jackson Lane
Lane Development LLC
PO Box 608
Eagle, ID 83616
Prepared by:
Western Consulting Group PLLC
1452 W Bannock Street
Boise, Idaho 83702
208-391-3715
Project Manager:
Kurt Norrell, PE, PMP
Project Engineer:
Kurt Norrell, PE, PMP
ID PE# 15461
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Original: April 20, 2023
Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
Table of Contents
INTRODUCTION AND PURPOSE .......................................................................3
A. BASIN CHARACTERISTICS .........................................................................3
A.1. Project Site........................................................................................3
A.2. Groundwater and Infiltration Rates....................................................3
A.3. Pre- and Post-Development Conditions............................................4
B. STORMWATER MANAGEMENT ..................................................................4
B.1. Public Stormwater Management .......................................................4
8.2. Private Stormwater Management......................................................5
B.3. Stormwater Calculations ...................................................................8
List of Appendices
Appendix 1 Stormwater Basin Map
Appendix 2 Stormwater Design Calculations
Appendix 3 Geotechnical Report & Infiltration Recommendation
Page 2
Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
INTRODUCTION AND PURPOSE
The purpose of this memorandum is to provide stormwater documentation to the
Ada County Highway District for the development of the Lennon Pointe Subdivision
encompassing the 10.41-acre property located at 1515 West Ustick Road,
Meridian, Idaho. The project site lies in the southeast corner of the intersection of
North Linder and West Ustick Road in the NW'/4 of Section 1, Township 3N, Range
1 W. The development is characterized as a mixed-use community with residential
townhomes, single-family attached and detached, multi-family, and commercial
land uses. A description of the development site is provided below.
A. BASIN CHARACTERISTICS
A.I. Project Site
The project site is an existing single-family residence and agricultural pasture. The
site will be improved with 61 residential units, 2 commercial lots, and 1.64 acres of
open space. Development will include one driveway access each from North
Linder and West Ustick Roads, a private street extending through the site, and an
extension of the public street that currently terminates at the property on eastern
and southern borders. Associated parking lots, utilities, stormwater facilities and
landscaping will accompany the development effort.
In general, the site drains from the northeast to the southwest. Two sizeable
waterways exist on the site. The Kellogg Drain and Creason Lateral traverse the
southern portion of the site from east to west and southeast to northwest
respectively. The Kellogg Drain is piped upstream and downstream of the project
site and will be piped through the project site as a result of the development effort.
The Creason Lateral is an open channel upstream and through the project site and
piped downstream of the project site. There will not be any impact to the Creason
Lateral as a result of the Lennon Pointe Development. The subdivisions to the east
and south of the subject property are topographically higher, resulting in drainage
to the site. A small irrigation ditch that originates from an irrigation vault in the
northeast project site will be piped south to the Kellogg Drain. The southwest half
of the site is located within the FEMA floodway and 100-year floodplain. Much of
the remainder of the site is within the 500-year floodplain.
A.2. Groundwater and Infiltration Rates
A geotechnical investigation was performed by Atlas Technical Consultants, LLC
(Atlas). The resulting report was prepared by Atlas and dated June 25, 2021
(13211602g). Four test pits were conducted with groundwater depths ranging from
5.3 to 8.4 feet below the ground surface. An addendum to the Atlas Geotechnical
investigation was made on November 8, 2021 to present the results of infiltration
testing for our test pit locations. Infiltration rates ranged from 0.48 to 2.16 inches
per hour. The geotechnical report and addendum are included with this
memorandum.
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Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
A.3. Pre- and Post-Development Conditions
The pre-developed site conditions include single-family residential with gravel
driveway, open lawn with sparse trees, open pasture with herbaceous vegetation
and a small amount of bare earth. A small amount of impervious area within the
existing parcel boundary includes rooftops for the single-family residence and
accessory buildings.
The post-developed site conditions will be a mixed-use community with residential
units, commercial lots, landscaping, and open space. Impervious areas will include
rooftops, roadways, sidewalks, parking lots, driveways, and access pathways.
Post-development runoff will be managed and infiltrated within the development
area. Both public and private facilities have been designed. The post-development
runoff coefficients (C) are provided for each basin area on the Stormwater Basin
Map (Appendix A) and range from 0.35 to 0.80. In general, a runoff coefficient of
0.70 was selected for commercial and residential lots and is on the higher range
of values used for urban neighborhoods and apartment dwellings (areas 1, 5, 7
10-23, an 28). When a higher percentage of the drainage basin consisted of
roadways or rooftops, the value was increased to 0.75 (areas 24 and 27) or 0.80
(areas 2-4, 6 and 9). The open space basin (area 25) was assigned a C value of
0.35, a conservative value for playgrounds and parks.
B. STORMWATER MANAGEMENT
B.I. Public Stormwater Management
Stormwater originating from the public road will be managed and infiltrated on-site
in one of three underground seepage beds with stormwater chambers (Facility 11,
22, and 28). Seepage beds will be installed in accordance with BMP 20 of the 2017
ACHD stormwater supplement. Stormwater chambers shall be Stormtech® SC-
740 chambers and will be installed in accordance with the manufacturer's
specifications. Pre-treatment to the seepage beds will be provided by either a sand
and grease trap (ISPWC SD-624) for flows greater than 1.0 cfs or a sediment
manhole (ISPWC-SD 611) for flows less than 1.0 cfs. A minimum of 1.0 feet of
cover from the top of the seepage bed to the pavement subgrade is provided. A
minimum of 3.0 feet of separation between the bottom of the drain rock and
groundwater is provided. The dimensions and depth of drain rock vary with each
seepage bed and are provided below. A summary of the public stormwater facilities
is provided in Table 1.
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Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report GROUP
Table 1. Stormwater design information for public facility 11, 22, and 28 including drainage area in acres
(area), peak stormwater discharge at the 100-year event (QPEAK) in cubic feet per second (CFS), runoff
volume at the 100-year event in cubic feet(CF)and design infiltration rate in inches per hour(in/hr).
DESIGN
PUBLIC AREA QPEAK RUNOFF VOLUME INFILTRATION
FACILITY AC CFS (CF) RATE (IN/HR)
11 0.52 0.94 1,265 0.6
22 0.53 0.96 1 ,289 0.6
28 0.63 1 .15 1 ,541 0.65
Facility 11 is located to the south of West Pebblestone Drive where it enters the
subdivision from the east. Facility 11 will have seven (7) Stormtech® SC-740
chambers. Two storm drain inlets (ACHD SD-604A) will convey flow through a 12"
HDPP pipe to a sediment manhole (ACHD SD-611) for pre-treatment. The
underground seepage bed shall have dimensions of 10 ft W x 51 ft L x 3.5 ft D.
Facility 22 is located on the west side of North Zion Road. Facility 22 will have eight
(8) Stormtech® SC-740 chambers. Two storm drain inlets (ACHD SD-604A) will
convey flow through a 12" HDPP pipe to a sediment manhole (ACHD SD-611) for
pre-treatment. The underground seepage bed shall have dimensions of 6.5 ft W x
75 ft L x 3.5 ft D. Where sewer services conflict with the seepage bed, the services
will be sleeved through the seepage bed per SD-07 of the 2017 ACHD stormwater
design guidelines.
Facility 28 is located on the west side of North Zion Road. Facility 28 will have
seven (7) Stormtech®SC-740 chambers. Two storm drain inlets (ACHD SD-604A)
will convey flow through a 12" HDPP pipe to a sand and grease trap (ISPWC SD-
624) for pre-treatment. The underground seepage bed shall have dimensions of 9
ft W x 62 ft L x 4.5 ft D. Where sewer services conflict with the seepage bed, the
services will be sleeved through the seepage bed per SD-07 of the 2017 ACHD
stormwater design guidelines.
B.2. Private Stormwater Management
There are 25 private stormwater management facilities for the Lennon Pointe
Subdivision. Three different types of facilities were used and include bioretention
swales (ACHD BMP30/IDEQ BMP 18), permeable pavers (ACHD BMP 34/IDEQ
BMP 19), and bioretention planters (ACHD BMP 31/IDEQ BMP 21). In general, the
private stormwater facilities have small contributing drainage areas to keep the
facilities shallow and to distribute infiltration capacity across the site. A summary
of the private stormwater facilities is provided in Table 2 and described below.
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Lennon Pointe Subdivision
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Stormwater Management Report G R O U P
Table 2. Stormwater design information for private facilities including drainage area in acres (area), peak
stormwater discharge at the 100-year event (QPEAK) in cubic feet per second (CFS), runoff volume at the
100-year event in cubic feet(CF) and design infiltration rate in inches per hour(in/hr).
DESIGN
PRIVATE AREA QPEAK RUNOFF VOLUME INFILTRATION
FACILITY (AC) (CFS) (CF) RATE (IN/HR)
BIORETENTION SWALES
1 0.40 0.73 979 0.5
2 0.81 1.67 2,237 0.6
12 0.17 0.30 401 0.5
13 0.18 0.33 446 0.5
14 0.12 0.22 289 0.5
15 0.13 0.23 314 0.5
16 0.12 0.22 290 0.5
17 0.12 0.22 291 0.5
18 0.13 0.23 312 0.5
19 0.07 0.12 164 0.5
20 0.07 0.12 160 0.25
21 0.12 0.22 292 0.25
25 0.83 0.75 1,007 0.25
26 0.82 1.41 1,884 0.25
PERMEABLE PAVERS
3 0.58 1.20 1,608 0.5
5 0.36 0.65 866 0.5
8 0.11 0.20 274 0.5
10 0.48 0.86 1,151 0.5
23 0.45 0.81 1,080 0.5
24 0.24 0.46 615 0.5
27 0.08 0.15 202 0.5
BIORETENTION PLANTERS
4 0.10 0.20 267 0.5
6 0.16 0.32 430 0.5
7 0.15 0.31 413 0.5
9 0.12 0.26 345 0.5
Facility 1 and 2 are in the northwest portion of the site on the commercial
development lot. Stormwater to facility 1 will be conveyed with a shallow v-ditch to
an 8" ADS HDPE pipe that goes under a sidewalk. Stormwater to facility 2 will be
conveyed from adjacent parking lots to a shallow inlet with attached walk per
ACHD SD-715A. Each facility has a 3:1 side slope. Both facilities 1 and 2 will have
2 feet of bioretention soil media (BSM). No gravel storage layer is required for
either facility.
Facility 3 is in the northwest portion of the site and consists of permeable pavers
on West Pebblestone Lane. The paver length and width are 126 feet and 16 feet
respectively for a total area of 2,016 square feet. An aggregate storage layer 2 feet
in depth will be installed below the pavers. The entire runoff volume was designed
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Lennon Pointe Subdivision
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Stormwater Management Report G R O U P
to be stored within the aggregate storage layer. Permeable pavers shall conform
to the design specifications in ACHD BMP 34.
Facility 4 and 7 are private bioretention planters with concrete curb opening inlets
per ACHD SD-716. The curb surrounding the bioretention planter will be 6-inch
vertical curb and gutter per ACHD SD-701. Facility 4 has a surface area of 240
square feet with a depth of 8 inches. Facility 7 has a surface area of 360 square
feet with a depth of 8 inches. Both facilities 4 and 7 have 2 feet of BSM and half a
foot of drain rock. Inlets to the planters will be SD-715A shallow inlet attached walk
per the Construction Drawings.
Facility 5, 8, and 10 are in the northeast portion of the site and consist of permeable
pavers within private parking areas. Facilities 5 and 10 are 95 foot long by 18 foot
wide. The depth of storage stone in facility 5 is 16 inches. The depth of storage
stone in facility 10 is 21 inches. Facility 8 is 67 foot long by 6 foot wide with a 21
inches of storage stone. The entire runoff volume was designed to be stored within
the aggregate storage layer. Permeable pavers shall conform to the design
specifications in ACHD BMP 34.
Facility 6 and 9 are bioretention planters in the northeast portion of the site that
manage stormwater from private roadways. Stormwater is conveyed from the
roadway through shallow inlets with attached walk per ACHD SD-715A. Both
facilities 6 and 9 have a surface area of 640 square feet, depth of 6 inches, and 2
feet of BSM. Neither facility requires storage stone. Inlets to the planters will be
SD-716 curb opening inlet per the Construction Drawings.
Facilities 12 through 21 are private bioretention swales in the center of the site in
the common space between townhomes. The swales are meant to be shallow
depressions 9 inches deep with 3:1 side slopes, 2 feet of BSM, and a gravel
storage layer of varying depth. Gravel storage layer depths are reported in a table
on sheet C-3.6 of the Construction Drawings.
Facilities 23 and 24 are permeable pavers in the southwestern portion of the site
the manage stormwater from private roadways. Facility 23 consists of two private
parking areas that are hydraulically connected with a concrete curb channel with
14-inch-wide cast iron grate per detail 6, sheet CD-4.0 of the Construction
Drawings. Facility 23 has a surface area of 1 ,714 square feet with 21 inches of
gravel storage. Facility 24 has a surface area of 704 square feet with 2.2 feet of
gravel storage. The entire runoff volume was designed to be stored within the
aggregate storage layer. Permeable pavers shall conform to the design
specifications in ACHD BMP 34.
Facility 25 and 26 are private bioretention swales in the southwestern portion of
the site. Facility 25 is a shallow depression 0.25 feet deep with 3:1 side slopes and
2 feet of BSM. No gravel storage layer is required for either facility. Facility 26 is
the largest bioretention swale and has two conveyance inlets, one to the north,
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Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
and one to the east. The northern conveyance is from an inlet catch basin for rolled
curb and gutter per ACHD SD-604A to an 8" HDPP pipe. The eastern inlet will
collect runoff in a 6-inch-wide by 4-inch-deep trench drain with Class D rated cast
iron grate installed across the private driveway in the southeast corner of the site.
Each section of trench drain will outlet to the bottom with a 4-inch schedule 80 PVC
pipe which will key into the top of an 8-inch C900 PVC pipe underdrain. Runoff will
then be conveyed to a standard concrete manhole (ACHD SD-611). From the
manhole, runoff will be conveyed to the bioretention swale in an 8-inch HDPE pipe.
B.3. Stormwater Calculations
All stormwater facilities were sized to infiltrate the 100-year design storm. The
ACHD Calculation Sheet for Finding Peak Discharge/Volume (Version 10.5,
November 2018) based on the Rational Method was used to calculate the 100-
year runoff volume and peak discharge for each drainage facility (Appendix 2).
The 100-year velocity for storm drain pipes was calculated using FHWA's
Hydraulic Toolbox software (version 5.1.4.0, August 9, 2021) using Manning's
Equation. Results are provided in Appendix 2. The design infiltration rate used in
the calculation is the minimum infiltration rate required to infiltrate 90% of the runoff
volume in 48 hours. In all cases, the infiltration test results from the geotechnical
report (Atlas No. B211602g, Appendix C) are a minimum of 2 times greater than
the design infiltration rate used in the calculations.
Seepage beds were designed using the ACHD Calculation Sheet for Sizing
Seepage Beds with Optional Chambers. Seepage beds were sized such that the
100-year runoff volume was capable of being stored entirely within the Stormtech®
chambers and drain rock layers assuming a 0.4 void ratio for the drain rock.
Additionally, peak discharge calculations were also completed for each drop inlet
for the 25-year and 100-year design storms using the drainage area to each inlet.
The peak discharge of each drop inlet at the two design storms is provided on the
Storm Drain plan view sheets (sheet C-3.2 and C-3.4) of the Construction
Drawings. Velocities are provided on the facility profiles on sheet C-3.5 of the
Construction Drawings. Velocities through the Stormtech® chambers were not
calculated because the chambers are installed with no slope. Therefore, the
velocity is assumed to be significantly less than the velocity at the inlet of the
cambers/outlet of the 18-inch diameter non-perforated pipe based on the
chamber's much larger cross-sectional area. Outputs from Hydraulic Toolbox are
provided in Appendix 2.
Bioretention swales were sized using the ACHD Calculation Sheet for Sizing
Bioswales and Borrow Ditches and a modification to this spreadsheet for irregularly
shaped swales and swales requiring a gravel storage layer. The volume of
irregularly shaped swales was calculated in AutoCAD using the 3D surface.
Swales were sized to store the 100-year runoff volume within the swale, BSM, and
gravel storage layer. The gravel storage layer depth varies and is reported in the
table on sheet C-3.6 of the Construction Drawings. The porosity of the BSM and
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Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
drain rock was assumed to be 0.15 and 0.4 respectively. The gravel storage layer
will extend to the basin's top of bank.
Permeable pavers were sized using the ACHD Calculation Sheet for Permeable
Interlocking Concrete Pavers (PICP). The paver joint opening area was assumed
to be 0.10. The drain rock layer was assumed to have a porosity of 0.4. For all
facilities, the capacity of the paver joints was less than the peak discharge based
on the minimum time of concentration, 10 minutes. The entire runoff volume was
designed to be stored within the aggregate storage layer. Storage layer depths
vary and are reported in the table on sheet C-3.6 of the Construction Drawings.
Permeable pavers shall conform to the design specifications in ACHD BMP 34.
Bioretention planters were designed based on ACHD BMP 31 and sized to store
the 100-year runoff volume in the planter, BSM, and gravel storage layer. The
planter depth is measured from the surface of the BSM to the lower of the adjacent
sidewalk or curb elevation. The gravel storage layer depth varies and is reported
in the table on sheet C-3.6 of the Construction Drawings. For planters with SD-
715A shallow inlets, Hydraulic Toolbox was used to size the stormdrain pipes.
Outputs from Hydraulic Toolbox are provided in Appendix 2.
Page 9
Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
Appendix 1
Stormwater Basin Map
Page 10
\ LIST OF STORMWATER FACILTIES J
ZD
- - - - 1 PRIVATE BIORETENTION SWALE (ACHD BMP 30/IDEQ BMP 18) z �- - - - - - - - - -
- -
-�� �� �_ �� �_ 2 PRIVATE BIORETENTION SWALE (ACHD BMP 30/IDEQ BMP 18) OV 0
olrl_ I 3 PRIVATE PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19) w
4 PRIVATE BIORETENTION PLANTER (ACHD BMP 31/IDEQ BMP 21) w
7DA 1 i I I i 5 PRIVATE PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19) O
17635 SF
AREA 2 I AREA 5 ,,, 1 AREA 10
0.40 AC I 35245 SF 15595 SF 20725 SF
I I I I o 6 PRIVATE BIORETENTION PLANTER (ACHD BMP 31/IDEQ BMP 21)
C=0.70 0.81 AC 0.36 AC I I 0.48 AC
1 C-0.8�_ C=0.70 C=0.70
1 I- 1 _ _ - _ - 7 PRIVATE BIORETENTION PLANTER (ACHD BMP 31/IDEQ BMP 21)
1 FACILITY 5 (PRIVATE) - - - - - - - - - - - - - - - - -
I I -
I I I I I FACILITY 10 (PRIVATE)
- - 1 i I I I i I 8 PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19)
L LL LL L LL LL I 1
L LL LL L LL LL LL L LL LLI L I I AID 9 LL L LL LL LL_LLLL LL L LL L 9 BIORETENTION PLANTER (ACHD BMP 31/IDEQ BMP 21)
L LL LL L LL LL LL L LL LL L LL L LL LL L __LL
LL LL LL L LL L (�
_ _ _ L LL LL L LL LL LL L LL LL L I 5430 SF LL L LL LL L LL LL LL L LL L I U
0 AC LL L LL LL L _LLLL LL L LL L / J
+ + + + + + + + + + I 10 PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19)
6780 SF/0.16 ACC (PRIVATE) I - - - 11 PUBLIC SEEPAGE BED WITH STORAGE CHAMBERS (ACHD BMP 20)*
O �
0 - 12 - 21 PRIVATE BIORETENTION SWALES (IDEQ BMP 18) N
1 I I I + FACILITY (PUBLIC) \ * (D' U CD
L _ + LLLLLL LLLL LL _ \ / _ - - - - _ _ 22 PUBLIC SEEPAGE BED WITH STORAGE CHAMBERS (ACHD BMP 20) (D p co
AREA3 i • \/+++++ EA ILITY8 /// i z z
5335 S AR A 4 , , , / 1 / 4940 SF/0.11 AC i z 0
1 ��UO SF . / 1 _ (PRIVATE) i _ t 23 PRIVATE PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19) J Q -
I 0.5
C' 80 LLLLLLLLLLLLLLLLLLLLLLL LLLL LLLLLLLL _ C 80 _ �' ' �/ / I I I m CwI)
LLLLL LLLLLLLLLLLLLLLLL LEE LLLLLLLL - - - - - - / LIT 7 1 24 PRIVATE PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19) z
I %LLLLL LLLLLLLLLLLLLLLLL LLL LLLLLLLL FACILITY IVATE= / IVA E) / 1 I I N O
I
\� EA 7 \� i 1 I 22785 SF
AREA 11 ( ) O 25 PRIVATE BIORETENTION SWALE ACHD BMP 30/IDEQ BMP 18 U L co1 3 I �, AREA 12 1 I 0 52 AC z
=0.80 7220 SF/0.17 AC 1
C-0.7o i I C=0.70 26 PRIVATE BIORETENTION SWALE (ACHD BMP 30/IDEQ BMP 18) LLI
1 i U)
i r i 1 27 PRIVATE PERMEABLE PAVERS (ACHD BMP 34/IDEQ BMP 19) LLI
A13 1 I
\\ 1 I I
803 AC FACILITY 12 (PRIVATE) I 28 PUBLIC SEEPAGE BED WITH STORAGE CHAMBERS (ACHD BMP 20)**
1 \\ I I 1 \ AREA 14 11
5212 SF/0.12 AC I i * SEDIMENT MANHOLE (ACHD SD-611) AS PRE-TREATMENT BMP
El
I C-0.70 , w
\ 0 1 ~
/ IT ` 1 1 ' � 1 I E] 1 ` **SAND AND GREASE TRAP (ISPWC SD-624) AS PRE-TREATMENT BMP o
\�� I I I FACILITY 13 (PRIV TE) I I o
I \ I
AREA 15 FAC LITY" 14 (PRl\7AT� I m
\ I I 5630 SF/0.13 AC 1 I
\ I AREA 16 I 1 \
I C=0 5223 SF/0.12 AC i A\RJ21 �' PUBLIC FACILITY NARRATIVES
AREA 23 ' r C=0.70 23205 SFI
19455 SF0.45 AC \ I o 0.5 AC FACILITY 11 - FACILITY 11 IS AN UNDERGROUND SEEPAGE BED WITH SEVEN (7) STORMTECH SC-740 z
FACILITY 15 (PRIV ) ' - 0 C=0.70 i 1 8 0
CHAMBERS. TWO STORMDRAIN INLETS (ACHD SD-604A) WILL CONVEY FLOW THROUGH 0
' 1 I i FAC LITY 16 (PRIMA-T_E) I I A 12" HDPP PIPE TO A SEDIMENT MANHOLE (ACHD SD-611) FOR PRE-TREATMENT. THE w
AREA 17
LLLL i \ 5247 AREA
12 AC AREA Er 18 j F CILI I 2 (PURL UNDERGROUND SEEPAGE BED SHALL HAVE DIMENSIONS OF 10 FT W X 51 FT L X 3.5 FT
I ' LLLL \ 1 C-0.70 5617 SF/0.13 AC 1 D AND WILL BE BUILT ACCORDING TO ACHD BMP 20 DETAILS AND NOTES.
LLLL I C=0.70
I ' LLLL I 1 \ II o FACILITY 22 - FACILITY 22 IS AN UNDERGROUND SEEPAGE BED WITH EIGHT (8) STORMTECH SC-740
_LLLLLL
IL 1 I CHAMBERS. TWO STORMDRAIN INLETS (ACHD SD 604A) WILL CONVEY FLOW THROUGH
-LLLLL' -LLLLL I CI (PRIV TE) I o A 12" HDPP PIPE TO A SEDIMENT MANHOLE (ACHD SD-611) FOR PRE-TREATMENT. THE
LLLL I E �r FAC LITY 18 (PRIVATE) I
\ LLLL 19 ! I UNDERGROUND SEEPAGE BED SHALL HAVE DIMENSIONS OF 6.5 FT W X 75 FT L X 3.5 FT
\ LLLL 1 4 SF 2952 7 A I AREA 20 1 I D AND WILL BE BUILT ACCORDING TO ACHD BMP 20 DETAILS AND NOTES. WHERE
LLLL I 4 AC C= 2883 SF/0.07 AC I AREA 28 N
_ _ F ITY 23 (PRIVATE) LLLL = E 1277 0 SF \ SEWER SERVICES CONFLICT WITH THE SEEPAGE BED, THE SERVICES WILL BE SLEEVED o
r \ FA C=0.RI I 6 AC THROUGH THE SEEPAGE BED PER SD-07 OF THE 2017 ACHD STORMWATER DESIGN N
0 � r
\ C- .70 GUIDELINES. N
LL AREA 21 1 \ 1 o U U Y Y
LLLL LLLLL 5265 SF/0.12 AC F CI I1 Y (PU
\ \ r�r-----� LLLLL C=0.70 FACILITY 28 - FACILITY 28 IS AN UNDERGROUND SEEPAGE BED WITH SEVEN 7 STORMTECH SC-740 o
�C LLL LLLLL \ LITY 21 PRIVATE ( ) O z z Lu >
LLL \ \ FAC ( _ ) CHAMBERS. TWO STORMDRAIN INLETS ACHD SD-604A WILL CONVEY FLOW THROUGH Z o
\ LL ( ) - w w
O Q U)
��62MSRr� L C L 7 w = w
\ rrr I LLLL A 12 HDPP PIPE TO A SAND AND GREASE TRAP (ISPWC SD-624) FOR PRE-TREATMENT. a o o Q
THE UNDERGROUND SEEPAGE BED SHALL HAVE DIMENSIONS OF 9 FT W X 62 FT L X 4.5
rrrr� CILITY 24 (PRIVATE\ L LL L L FT D AND WILL BE BUILT ACCORDING TO ACHD BMP 20 DETAILS AND NOTES. WHERE
r �r�
A E - SEWER SERVICES CONFLICT WITH THE SEEPAGE BED, THE SERVICES WILL BE SLEEVED W
�0 THROUGH THE SEEPAGE BED PER SD-07 OF THE 2017 ACHD STORMWATER DESIGN
13370� AREA 26. �� ��' 7� �
AGILITY 25 (P \ GUIDELINES.
�= C=0.75 z
/0.39 AC W W Z
LEGEND Z Cn
Z
- O a- Q
I r / PUBLIC FACILITY DRAINAGE BASIN BOUNDARY O p m
\1 r r----~---- PRIVATE FACILITY DRAINAGE BASIN BOUNDARY z > W W
J 4LLLLLLL9LL
LLLLLLLLL LLLLLLL PERVIOUS INTERLOCKING CONCRETE PAVERS O m W ~
I � LLLLLLL Q Q
-�� \ ACHD BMP 34 Z
77FACILITY 26 PRIVATE) / \ Z
II +++++++++ BIO RETENTION PLANTER W
ACHD BMP 31 J
O
BIO RETENTION SWALE
ACHD BMP 30
STORMWATER BASIN MAP 0 40 80 CURB OPENING INLET
SCALE: 1" = 40' Feet DI ISPWC SD-716
SHEET NO:
SHALLOW INLET ATTACHED TO WALK E-1.0
um ACHD SUPPLEMENT TO THE ISPWC SD-715A
DATE:
4-10-2023
PAGE NO:
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Stormwater Management Report G R O U P
Appendix 2
Stormwater Design Calculations
Page 11
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 1
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities (25 max) 12
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 17,635
Acres 0.40
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge (QPeak) Qpeak 0.73 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 979 ft Single Family 0.35-0.50Multi-family 0.60-0.75
V=CI (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 612 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 98 ftj Concrete 0.95
Primary Treatment/Storage Basin V 881 W Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor (See BMP 20 Tab) V 979 ft3 Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
I Project Name Lennon Pointe- Facility 1- Infiltration basin
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.40 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 979 979.00 ft3
6 Length of Swale 1 ft *Calcs not applicable, not a
rectangular swale. Modified.
7 Infiltration Window? (Note:infiltration required if Longitudinal Slope<1%)
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Width 826.00 ft
14 Total Swale Capacity Without Driveways 0 985.50 ft3 Volume from CAD
15 Does it Have Capacity? OK Calc Modified to use volume
16 Time to Drain 28.4 hr
90%volume in 48-hours minimum OK
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 2
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 35,245
Acres 0.81
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 1.67 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 2,237 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 1,398 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 224 ftj Concrete 0.95
Primary Treatment/Storage Basin V 2,013 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 2,237 ftj gavel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Sizing Bioswales & Borrow Ditches
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result
in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe-Facility 2
2 Enter number of Bioswales/Borrow Ditches(25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.80 Link to: Q,v
4 Area A(Acres) 0.81 acres [Q,V2
QV3
Approved discharge rate for the given storm(if applicable) 0.00 cfs QV4
5 Design Vol With 0%Sed for Swales V 2,237 2150.00 ft3 Qv5
6 Length of Swale 38 ft
7 Infiltration Window?(Note:infiltration required if Longitudinal Slope<1%)
Design Infiltration Rate 0.60 in/hr
8 Infiltration Window Width 25.00 ft
9 Set Swale Bottom Width b 25.00 ft
10 Set Swale Top Width 40.00 ft
11 Set Swale Depth y 2.50 ft
12 Swale Side Slopes H:l Sxs 3.00
13 Calculate cross-sectional area AXS 81.25 ftz
AXS=y z z+by
14 Total Swale Capacity Without Driveways 3,088 ft3
15 Does it Have Capacity? OK
16 Time to Drain 45.3 hr
90%volume in 48-hours minimum OK
Check Swale With Driveways
17 Avg.Driveway Fill Slope in Swale (H/V) 0.00 ft/ft
18 Enter Total Number of Driveways 0 ea 0.0 ft3 Deduct driveway slope
19 Enter Total Length of all Driveways ft 0.0 ft3 Deduct driveway length
20 Lost Swale Length From Trees,etc. ft 0.0 ft3 Deduct other
21 Adjusted Length of Infiltration Area 0.0 ft
22 Excess Capacity=Storage-Deductions-Runoff Volume 937.5 ft3
23 Is Capacity Good? YES
24 Time to Drain 0.0 hr
90%volume in 48-hours minimum OK
https:Hwcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Design/Design/Calcs/Stormwater CaIcs/ACHD_SD_CALCS_Len non Pt_FaciIityl-12.xlsm 4/9/2023,9:27 AM
Version 10.0, May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 3
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 25,335
Acres 0.58
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 1.20 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 1,608 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 1,005 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 161 ftj Concrete 0.95
Primary Treatment/Storage Basin V 1,447 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 1,608 ftj gavel Fields: Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 3
Runoff Calculations
1 Design Storm 100 Link to: Q,V
2 Weighted Runoff Coefficient C 0.80 QV2
[Q,v3
3 Area A (Acres) 0.58 acres QV4
4 Approved Discharge Rate (if applicable) 0.00 cfs Q,VS
Q,V6
5 Design Volume V 1,608 ft3 Q,V7
Q,V8
Paver&Aggregate Details
6 Enter Total Paver Area Length L 126.00 ft
7 Enter Total Paver Area Width W 16.00 ft
8 Total Paver Area A 2,016 ftz
9 Paver Joint Opening Area per Manf. Spec 0.10 Assume 0.10
10 Depth of Storage Stone 2.00 ft
11 Void Factor of Storage Stone (0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAval 1,613 ft'
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.50 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate: #8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 1.20 cfs
19 Capacity of Paver Joints QPeak_Pavers 2.33 cfs
20
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Design/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_Len non Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.0, May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 4
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 4,200
Acres 0.10
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.20 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 267 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 167 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 27 ftj Concrete 0.95
Primary Treatment/Storage Basin V 240 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 267 ftj gavel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
I Project Name Lennon Pointe- Facility 4- Bioretention Planter
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.80 Link to:
4 Area A(Acres) 0.10 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 267 267.00 ft3
6 Area of Planter 240 ft2
7 Infiltration Window? (Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 240.00 ft2
11 Set Planter Depth y 0.67 ft
14 Total Planter Capacity Above Ground 161 ft3
15 Does it Have Capacity? -*see additional storage below
16 Time to Drain 26.7 hr
90%volume in 48-hours minimum OK
Swale Media Storage
17 Depth of BSM 2.00 ft
18 Porosity of BSM 0.15 Additional storage provided in Swale
19 BSM Storage 72.0 ft3 media
20 Depth of Drainrock 0.5 ft
21 Porosity of Drainrock 0.4
22 Drainrock Storage 48.0 ft3
23 Total Storage (Media +Swale) 280.8
24 Is Capacity Good? YES
25 Time to Drain 26.7 hr
90%volume in 48-hours minimum OK
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 5
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 15,595
Acres 0.36
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.65 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 866 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 541 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 87 ftj Concrete 0.95
Primary Treatment/Storage Basin V 779 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 866 ftj gavel Fields: Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 5
Runoff Calculations
1 Design Storm 100 Link to: Q,V
2 Weighted Runoff Coefficient C 0.70 QV2
Q,v3
3 Area A (Acres) 0.36 acres QV4
4 Approved Discharge Rate (if applicable) 0.00 cfs [Q'V5
Q,V6
5 Design Volume V 866 ft3 Q,V7
Q,V8
Paver&Aggregate Details
6 Enter Total Paver Area Length L 18.00 ft
7 Enter Total Paver Area Width W 95.00 ft
8 Total Paver Area A 1,710 ftz
9 Paver Joint Opening Area per Manf. Spec 0.10 Assume 0.10
10 Depth of Storage Stone 1.33 ft
11 Void Factor of Storage Stone (0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAval 910 ft'
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.50 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate: #8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.65 cfs
19 Capacity of Paver Joints QPeak_Pavers 1.98 cfs
20
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Design/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_Len non Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.0, May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 6
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 6,780
Acres 0.16
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.32 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 430 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 269 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 43 ftj Concrete 0.95
Primary Treatment/Storage Basin V 387 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 430 ftj gavel Fields: Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
I Project Name Lennon Pointe- Facility 6 Bioretention Planter
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.80 Link to:
4 Area A(Acres) 0.10 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 430 430.00 ft3
6 Area of Planter 640 ft2
7 Infiltration Window? (Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 640.00 ft2
11 Set Planter Depth y 0.50 ft
14 Total Planter Capacity Above Ground 320 ft3
15 Does it Have Capacity? -*see additional storage below
16 Time to Drain 16.1 hr
90%volume in 48-hours minimum OK
Swale Media Storage
17 Depth of BSM 2.00 ft
18 Porosity of BSM 0.15
19 BSM Storage 192.0 ft3 Additional storage provided in swale
20 Depth of Drainrock 0 ft media
21 Porosity of Drainrock 0.35
22 Drainrock Storage 0.0 ft3
23 Total Storage (Media +Swale) 512.0
24 Is Capacity Good? YES
25 Time to Drain 16.125 hr
90%volume in 48-hours minimum OK
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
ca cu ate
Calculate Post-Development Flows (for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 7
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 6,505
Acres 0.15
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.31 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 413 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 258 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 41 ftj Concrete 0.95
Primary Treatment/Storage Basin V 372 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 413 ftj Gravel Fields: Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
I Project Name Lennon Pointe- Facility 7- Bioretention Planter
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.80 Link to:
4 Area A(Acres) 0.15 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 413 ft3
6 Area of Planter 360 ft2
7 Infiltration Window? (Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 360.00 ft2
11 Set Planter Depth y 0.67 ft
14 Total Planter Capacity Above Ground 241 ft3
15 Does it Have Capacity? *see additional storage below
16 Time to Drain 27.5 hr
90%volume in 48-hours minimum OK
Swale Media Storage
17 Depth of BSM 2.00 ft
18 Porosity of BSM 0.15 Additional storage provided in Swale
19 BSM Storage 108.0 ft3 media
20 Depth of Drainrock 0.5 ft
21 Porosity of Drainrock 0.4
22 Drainrock Storage 72.0 ft3
23 Total Storage (Media +Swale) 421.2
24 Is Capacity Good? YES
25 Time to Drain 27.53333 hr
90%volume in 48-hours minimum OK
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 8
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 4,940
Acres 0.11
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "(
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.20 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol (V) (for sizing primary storage) V 274 ft Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 171 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks, Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 27 ftj Concrete 0.95
Primary Treatment/Storage Basin V 247 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor (See BMP 20 Tab) V 274 ftj Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 8
Runoff Calculations
1 Design Storm 100 Link to: Q,V
2 Weighted Runoff Coefficient C 0.70 QV2
Q,v3
3 Area A (Acres) 0.11 acres QV4
4 Approved Discharge Rate (if applicable) 0.00 cfs Q,VS
Q,V6
5 Design Volume V 274 ft3 QV7
fQ,v8
Paver&Aggregate Details
6 Enter Total Paver Area Length L 67.00 ft
7 Enter Total Paver Area Width W 6.00 ft
8 Total Paver Area A 402 ft2
9 Paver Joint Opening Area per Manf. Spec 0.10 Assume 0.10
10 Depth of Storage Stone 1.75 ft
11 Void Factor of Storage Stone (0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAval 281 ft'
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.50 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate: #8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.20 cfs
19 Capacity of Paver Joints QPeak_Pavers 0.47 cfs
20
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Design/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_Len non Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.0, May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 9
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,430
Acres 0.12
6 Determine the Weighted Runoff Coefficient (C) 0.80
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.80
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.26 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 345 ft Single Family 0.35-0.50Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 215 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 34 ftj Concrete 0.95
Primary Treatment/Storage Basin V 310 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor (See BMP 20 Tab) V 345 ftj Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
I Project Name Lennon Pointe- New Facility 9
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.90 Link to:
4 Area A(Acres) 0.12 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 388 ft3
6 Area of Planter 640 ft2
7 Infiltration Window? (Note:infiltration required if Longitudinal Sloped%)
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 640.00 ft2
11 Set Planter Depth y 0.50 ft
14 Total Planter Capacity Above Ground 320 ft3
15 Does it Have Capacity? -*see additional storage below
16 Time to Drain 14.6 hr
90%volume in 48-hours minimum OK
Swale Media Storage
17 Depth of BSM 2.00 ft
18 Porosity of BSM 0.15 Additional storage provided in Swale
19 BSM Storage 192.0 ft3 media
20 Depth of Drainrock 0 ft
21 Porosity of Drainrock 0.4
22 Drainrock Storage 0.0 ft3
23 Total Storage (Media +Swale) 512.0
24 Is Capacity Good? YES
25 Time to Drain 14.55 hr
90%volume in 48-hours minimum OK
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 10
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 20,725
Acres 0.48
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.86 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 1,151 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 719 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 115 ftj Concrete 0.95
Primary Treatment/Storage Basin V 1,036 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 1,151 ftj gavel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 10
Runoff Calculations
1 Design Storm 100 Link to: QV6
2 Weighted Runoff Coefficient C 0.70 Q'v7
Qvs
3 Area A (Acres) 0.48 acres Q,V9
4 Approved Discharge Rate (if applicable) 0.00 cfs [Q,vi1
Q,v11
5 Design Volume V 1,151 ft3 QV12
QV TR55
Paver&Aggregate Details
6 Enter Total Paver Area Length L 95.00 ft
7 Enter Total Paver Area Width W 18.00 ft
8 Total Paver Area A 1,710 ft2
9 Paver Joint Opening Area per Manf. Spec 0.10 Assume 0.10
10 Depth of Storage Stone 1.75 ft
11 Void Factor of Storage Stone (0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAval 1,197 ft'
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.60 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate: #8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.86 cfs
19 Capacity of Paver Joints QPeak_Pavers 1.98 cfs
20
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Design/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_Len non Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.0, May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe, Facility 11(Total)
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 22,785
Acres 0.52
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.94 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 1,265 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.1so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 791 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Asphalt 0.95
Basin Forebay V 127 ftj Concrete 0.95
Primary Treatment/Storage Basin V 1,139 ftj Brick 0.95
Subsurface Storage Roofs o.95
Volume Without Sediment Factor (See BMP 20 Tab) V 1,265 ftj gavel Fields: Sandy soil Soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/3/2023, 10:54 AM
Version 10.5, November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 11,Drop Inlet West 100-year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 7,297
Acres 0.17
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.30 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(far sizing primary storage) V 405 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 253 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 41 ft' Concrete 0.95
Primary Treatment/StorageBasin V 365 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 405 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/4/2023,11:28 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 11,Drop Inlet West 25-year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 7,297
Acres 0.17
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.22 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 291 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 253 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 29 ft' Concrete 0.95
Primary Treatment/StorageBasin V 262 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 291 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/4/2023,11:28 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 11,Drop Inlet East,100-year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 15,488
Acres 0.36
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.64 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(far sizing primary storage) V 860 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 538 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 86 ft' Concrete 0.95
Primary Treatment/StorageBasin V 774 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 860 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/4/2023,11:28 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 11,Drop Inlet East,25-year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 15,488
Acres 0.36
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.46 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 618 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr S38 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 62 ft' Concrete 0.95
Primary Treatment/StorageBasin V 556 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 618 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl-12.xlsm 4/4/2023,11:28 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result
in facilities that meet or exceed these calculations in order to be accepted.
Note this spreadsheet pulls information from the"Peak QV"tab
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe,Facility 11
2 Enter number of Seepage Beds(25 max) 1
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.70 Link to: QV9
QV70
5 Area A(Acres) 0.52 acres low,i�
6 Approved discharge rate(if applicable) 0.00 cfs QV12
Q V13
7 Is Seepage Bed in Common Lot? Yes V 1,265 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 10.0 ft
9 Set Total Design Depth of All Drain Rock D 3.5 ft
Rock Only,Do Not Include Filter Sand Depth or Cover
10 Void Ratio of Drain Rock Voids 0.4
0.4 for 1.5"-2"drain rock and 3/4"Chips
11 Design Infiltration Rate(8 in/hr max) Perc 0.60 in/hr
12 Size of WQ Perf Pipe(Perf 180°) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 14.7 ft3/ft
15 Calculate Design Length L 86 51 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 51 ft
17 Variable Infiltration Window W SWW 10.0 ft
18 Time to Drain 44.7 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 51 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf-CdxAxV(2xgxH)
Optional Storage Chambers
Note:This assumes chambers are organized in a rectangular layout.
1-StormTech,
1 Type of Chambers SC740
2 Volume to Store V 517 ft3
3 Installed Chamber Width Cw 4.25 ft
Installed Chamber Depth Cd 2.50 ft
Installed Chamber Height Ch 7.12 ft
4 Chamber Void Factor
5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit
6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit
7 Total Number of Units Required 7 7 ea
8 Area of Infiltration Aperc 315 ft2
9 Volume Infiltration Vperc 16 ft3/hr
10 Time to Drain 29.5 hours
90%volume in 48-hours minimum
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_LennonPt_Facilityl-12.xlsm 4/9/2023,9:23 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
ca cu ate
Calculate Post-Development Flows (for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 12
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 7,220
Acres 0.17
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.30 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 401 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 251 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 40 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 361 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 401 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 12
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.18 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 401 ft3
6 Area of Microbioretention 397 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 397.00 ft2
1 Total Bioretention Capacity Above Ground 245 245.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 24.2 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 119.1 ft3 media
7 Depth of Drainrock 0.75 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 119.1 ft3
23 Total Storage (Media +Swale) 483.2
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 13
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities (25 max) 10
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 8,030
Acres 0.18
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge (QPeak) Qpeak 0.33 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 446 ft Single Family 0.35-0.50Multi-family 0.60-0.75
V=CI (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 279 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 45 W Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 401 W Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 446 ft3 Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 13
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.17 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 446 ft3
6 Area of Microbioretention 414 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 414.00 ft2
1 Total Bioretention Capacity Above Ground 141 141.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 25.9 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 124.2 ft3 media
7 Depth of Drainrock 1.25 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 207.0 ft3
23 Total Storage (Media +Swale) 472.2
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 14
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,212
Acres 0.12
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 289 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 181 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 29 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 261 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 289 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 14
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.12 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 289 ft3
6 Area of Microbioretention 264 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 264.00 ft2
1 Total Bioretention Capacity Above Ground 85 85.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 26.3 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 79.2 ft3 media
7 Depth of Drainrock 1.25 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 132.0 ft3
23 Total Storage (Media +Swale) 296.2
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 15
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,650
Acres 0.13
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.23 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 314 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 196 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 31 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 282 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 314 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 15
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.13 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 314 ft3
6 Area of Microbioretention 327 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 327.00 ft2
1 Total Bioretention Capacity Above Ground 156 156.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 23.0 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 98.1 ft3 media
7 Depth of Drainrock 0.5 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 65.4 ft3
23 Total Storage (Media +Swale) 319.5
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 16
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,223
Acres 0.12
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 290 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 181 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 29 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 261 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 290 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 16
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.12 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 290 ft3
6 Area of Microbioretention 287 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 287.00 ft2
1 Total Bioretention Capacity Above Ground 182 182.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 24.3 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 86.1 ft3 media
7 Depth of Drainrock 0.5 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 57.4 ft3
23 Total Storage (Media +Swale) 325.5
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 17
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,247
Acres 0.12
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 291 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 182 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 29 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 262 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 291 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 17
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.12 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 291 ft3
6 Area of Microbioretention 288 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 288.00 ft2
1 Total Bioretention Capacity Above Ground 106 106.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 24.3 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 86.4 ft3 media
7 Depth of Drainrock 1 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 115.2 ft3
23 Total Storage (Media +Swale) 307.6
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
ca cu ate
Calculate Post-Development Flows (for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 18
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,617
Acres 0.13
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.23 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 312 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 195 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 31 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 281 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 312 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 18
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.13 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 312 ft3
6 Area of Microbioretention 310 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 310.00 ft2
1 Total Bioretention Capacity Above Ground 120 120.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 24.2 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 93.0 ft3 media
7 Depth of Drainrock 1 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 124.0 ft3
23 Total Storage (Media +Swale) 337.0
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 19
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 2,952
Acres 0.07
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.12 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 164 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 102 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 16 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 148 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 164 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 19
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.07 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 164 ft3
6 Area of Microbioretention 140 ft2
7 Infiltration Window
Design Infiltration Rate 0.50 in/hr
8 Infiltration Window Area 140.00 ft2
1 Total Bioretention Capacity Above Ground 34 34.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 28.1 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 42.0 ft3 media
7 Depth of Drainrock 1.75 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 98.0 ft3
23 Total Storage (Media +Swale) 174.0
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 20
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 2,883
Acres 0.07
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.12 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 160 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 100 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 16 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 144 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 160 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
1 Project Name Lennon Pointe- Facility 20
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.07 acres
Approved discharge rate for the given storm (if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 160 ft3
6 Area of Microbioretention 169 ft2
7 Infiltration Window
Design Infiltration Rate 0.25 in/hr
8 Infiltration Window Area 169.00 ft2
1 Total Bioretention Capacity Above Ground 66 66.00 ft3 *Irregular shape, volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 45.4 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in Swale
6 BSM Storage 50.7 ft3 media
7 Depth of Drainrock 0.75 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 50.7 ft3
23 Total Storage (Media +Swale) 167.4
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume - Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
Calculate Post-Development Flows(for pre-development flows, increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe MicroBioretention Facility 21
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm (100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin (SF or Acres) SF 5,265
Acres 0.12
6 Determine the Weighted Runoff Coefficient (C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes (Tc) or use default 10 user Calculate
min
10 Min. Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients "t
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge (QPeak) Qpeak 0.22 cfs Urban neighborhoods 0.50-0.70
Residential
10 Calculate total runoff vol (V) (for sizing primary storage) V 292 ft Single Family 0.35-0.50
Multi-family 0.60-0.75
V=Ci (Tc=60)Ax3600 Residential (rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I (95th percentile=0.60 in) 95th 0.60 in Light areas D.so
Enter Runoff Reduction Vol (95th Percentile=0.60-in x Area x C) Vrr 183 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters (if applicable) cfs Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage: Basin Streets
Basin Foreba V 29 ftj Asphalt 0.95
Y Concrete 0.95
Primary Treatment/Storage Basin V 263 ftj Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor (See BMP 20 Tab) V 292 ftj Gravel 0.75
Fields: Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average: 2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https:Hwcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Lennon Pt_Facilityl3-22.xlsm 4/3/2023, 11:22 AM
Version 10.5, November 2018
I Project Name Lennon Pointe-Facility 21
2 Enter number of Bioswales/Borrow Ditches (25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.70 Link to:
4 Area A(Acres) 0.12 acres
Approved discharge rate for the given storm (if applicable 0.00 cfs
5 Design Vol With 0%Sed for Swales V 292 ft3
6 Area of Microbioretention 295 ftz
7 Infiltration Window
Design Infiltration Rate 0.25 in/hr *infiltration rate is 0.5x
8 Infiltration Window Area 295.00 ftz measured rate
1 Total Bioretention Capacity Above Ground 99 99.00 ft3 *Irregular shape,volume
measured in CAD
2 Does it Have Capacity? -*see additional storage below
3 Time to Drain 47.5 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 2.00 ft
5 Porosity of BSM 0.15 Additional storage provided in swale
6 BSM Storage 88.5 ft3 media
7 Depth of Drainrock 1 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 118.0 ft3
23 Total Storage (Media +Swale) 305.5
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
4 Enter number of storage facilities(25 max) 10
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 23,205
Acres 0.53
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
to Min. Estimated Runoff Coefficients for Various Surface
min
- Type of Surface Runoff Coefficients"(
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.96 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,289 ft3 Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 805 W Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Parks,cemeteries 0.20-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 129 ft' concrete 0.95
Primary Treatment/StorageBasin V 1,160 ft' Brick 0.95
Subsurface Storage Roofs 0.
Gravel 0.75
5
Volume Without Sediment Factor(See BMP 20 Tab) V 1,289 ft3 Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22Inlet W,100 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 6,010
Acres 0.14
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.25 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 334 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 209 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 33 ft' Concrete 0.95
Primary Treatment/StorageBasin V 300 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 334 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22Inlet W,25 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 6,010
Acres 0.14
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.18 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 240 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 209 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 24 ft' Concrete 0.95
Primary Treatment/StorageBasin V 216 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 240 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22 Inlet E,100 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 17,195
Acres 0.39
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.71 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 955 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr S97 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 95 ft' Concrete 0.95
Primary Treatment/StorageBasin V 859 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 955 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22 Inlet E,25 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 17,195
Acres 0.39
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.51 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 686 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 597 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 69 ft' Concrete 0.95
Primary Treatment/StorageBasin V 618 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 686 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result
in facilities that meet or exceed these calculations in order to be accepted.
Note this spreadsheet pulls information from the"Peak QV"tab
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 22
2 Enter number of Seepage Beds(25 max) 3
3 Design Storm 100
4 Weighted Runoff Coefficient C 0.70 Link to: QV
QV2
5 Area A(Acres) 0.53 acres QV3
6 Approved discharge rate(if applicable) 0.00 cfs QV4
VS
7 Is Seepage Bed in Common Lot? Yes V 1,289 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 6.5 ft
9 Set Total Design Depth of All Drain Rock D 3.5 ft
Rock Only,Do Not Include Filter Sand Depth or Cover
10 Void Ratio of Drain Rock Voids 0.4
0.4 for 1.5"-2"drain rock and 3/4"Chips
11 Design Infiltration Rate(8 in/hr max) Perc 0.60 in/hr
12 Size of WQ Perf Pipe(Perf 180°) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 9.6 ft3/ft
15 Calculate Design Length L 134 75 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 75 ft
17 Variable Infiltration Window W SWW 6.5 ft
18 Time to Drain 47.6 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 75 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf-CdxAxV(2xgxH)
Optional Storage Chambers
Note:This assumes chambers are organized in a rectangular layout.
1-StormTech,
1 Type of Chambers SC740
2 Volume to Store V 569 ft3
3 Installed Chamber Width Cw 4.25 ft
Installed Chamber Depth Cd 2.50 ft
Installed Chamber Height Ch 7.12 ft
4 Chamber Void Factor
5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit
6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit
7 Total Number of Units Required 8 8 ea
8 Area of Infiltration Aperc 275 ft2
9 Volume Infiltration Vperc 14 ft3/hr
10 Time to Drain 37.2 hours
90%volume in 48-hours minimum
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_LennonPt_Facility23-30.xlsm 4/9/2023,9:40 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 23
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 19,455
Acres 0.45
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.81 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,080 930 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 675 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 93 ft' Concrete 0.95
Primary Treatment/StorageBasin V 837 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 1,080 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe Facility 23
Runoff Calculations
1 Design Storm 100 Link to: QV
2 Weighted Runoff Coefficient C 0.70 Q,V2�
QV3
3 Area A(Acres) 0.45 acres Q,V4
0.00 cfs QV5
4 Approved Discharge Rate(if applicable) Q,v6
5 Design Volume V 1,080 ft3 Q V8
Q,vs
Paver&Aggregate Details
6 Enter Total Paver Area Length L 91.00 ft
7 Enter Total Paver Area Width W 18.83 ft
8 Total Paver Area A 1,714 ft2
9 Paver Joint Opening Area per Manf.Spec 0.10 Assume 0.10
10 Depth of Storage Stone 1.75 ft
11 Void Factor of Storage Stone(0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAvaii 1,199 ft3
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.48 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate:#8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.81 cfs
19 Capacity of Paver Joints QPeak_Pavers 1.98 cfs
20
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 24
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 10,343
Acres 0.24
6 Determine the Weighted Runoff Coefficient(C) 0.75
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.75
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.46 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 615 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 385 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 62 ft' Concrete 0.95
Primary Treatment/StorageBasin V 554 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 615 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe Facility 24
Runoff Calculations
1 Design Storm 100 Link to: QV
2 Weighted Runoff Coefficient C 0.75 Q,V2
Q,V3�
3 Area A(Acres) 0.24 acres Q,V4
0.00 cfs QV5
4 Approved Discharge Rate(if applicable) Q,v6
5 Design Volume V 615 ft3 QV7
QV8
Paver&Aggregate Details
6 Enter Total Paver Area Length L 32.00 ft
7 Enter Total Paver Area Width W 22.00 ft
8 Total Paver Area A 704 ft2
9 Paver Joint Opening Area per Manf.Spec 0.10 Assume 0.10
10 Depth of Storage Stone 2.20 ft
11 Void Factor of Storage Stone(0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAvaii 620 ftj
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.48 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate:#8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.46 cfs
19 Capacity of Paver Joints QPeak_Pavers 0.81 cfs
20
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 25
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 36,270
Acres 0.83
6 Determine the Weighted Runoff Coefficient(C) 0.35
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.35
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.75 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,007 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 629 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 101 ft' Concrete 0.95
Primary Treatment/StorageBasin V 906 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 1,007 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
1 Project Name Lennon Pointe-Facility 25
2 Enter number of Bioswales/Borrow Ditches(25 max) 1
3 Design Storm 100
Weighted Runoff Coefficient C 0.35 Link to:
4 Area A(Acres) 0.83 acres
Approved discharge rate for the given storm(if applicabl 0.00 cfs
5 Design Vol With 0%Sed for Swales V 1,007 ft3
6 Area of Microbioretention 3,670 ft2
7 Infiltration Window
Design Infiltration Rate 0.25 in/hr
8 Infiltration Window Area 3670.00 ftz
1 Total Bioretention Capacity Above Ground 2,750 2750.00 ft3 *Irregular shape,volume
measured in CAD
2 Does it Have Capacity? OK I
3 Time to Drain 13.2 hr
90%volume in 48-hours minimum OK
Swale Media Storage
4 Depth of BSM 0.00 ft
5 Porosity of BSM 0.15 Additional storage provided in swale
6 BSM Storage 0.0 ft3 media
7 Depth of Drainrock 0 ft
8 Porosity of Drainrock 0.4
9 Drainrock Storage 0.0 ft3
23 Total Storage(Media+Swale) 2,750.0
24 Is Capacity Good? YES
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 26
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 13,370 5,630 16,790
Acres 0.82
6 Determine the Weighted Runoff Coefficient(C) 0.75 0.35 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.66
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.41 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,884 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 1,178 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 188 ft' Concrete 0.95
Primary Treatment/StorageBasin V 1,696 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 1,884 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
rge Rate using th r post-developm
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 26.1
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 13,370
Acres 0.31
6 Determine the Weighted Runoff Coefficient(C) 0.75
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.75
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 user calculate
min 10 Min. I Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in hr Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge(QPeak) Qpeak 0.59 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) 79b ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vn 497 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cis Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin streets
Basin Foreba V 80 ft` Asphalt 0.95
Y Concrete 0.95
Primary Treatment/StorageBasin V 716 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 796 ft, Gravel 0.75
Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Len non Pt_Facility22-28.xlsm 4/10/2023,11:55 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology.These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
rge Rate using th r post-developm
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 26.3
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 Subbasin 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 16,790
Acres 0.39
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 user calculate
min 10 Min. I Estimated Runoff Coefficients for Various Surface
Type of Surface Runoff Coefficients"I
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc #95th
F0.6Oin
Business
Downtown areas 0.70-0.95
9 Calculate the Post-Development peak discharge(QPeak) Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoffvol(V)(for sizing primary storage) Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vn 583 ft' Heavy areas 0.90
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cis Parks,Cemeteries 0.10-0.25
Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin streets
Basin Foreba V 93 ft` Asphalt 0.95
Y Concrete 0.95
Primary Treatment/StorageBasin V 839 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Volume Without Sediment Factor(See BMP 20 Tab) V 932 ft, Gravel 0.75
Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_Len non Pt_Facility22-28.xlsm 4/10/2023,11:55 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Bioswales & Borrow Ditches
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's
calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that
meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe-Facility 26
2 Enter number of Bioswales/Borrow Ditches(25 max)
3 Design Storm 100
Weighted Runoff Coefficient C 0.66 Link to: Q,v3
4 Area A(Acres) 0.82 acres Q,va
[Q,vs
Approved discharge rate for the given storm(if applicable) 0.00 cfs Q,v6
5 Design Vol With 0%Sed for Swales V 1,884 ft3 QN7
6 Length of Swale 88 ft
7 Infiltration Window?(Note:infiltration required if Longitudinal Slope<10%)
Design Infiltration Rate 0.25 in/hr
8 Infiltration Window Width 23.00 ft
9 Set Swale Bottom Width b 3.00 ft
10 Set Swale Top Width 23.00 ft
11 Set Swale Depth y 2.75 ft
12 Swale Side Slopes H:1 Sxs 3.00
13 Calculate cross-sectional area Axs 30.94 ftz
Axs=Y zz+by
14 Total Swale Capacity Without Driveways 2,723 2484.00 ft'
15 Does it Have Capacity? OK
16 Time to Drain 44.7 hr
90%volume in 48-hours minimum OK
Check Swale With Driveways
17 Avg.Driveway Fill Slope in Swale (H/V) 0.00 ft/ft
18 Enter Total Number of Driveways 0 ea 0.0 ft3 Deduct driveway slope
19 Enter Total Length of all Driveways 0 ft 0.0 ft3 Deduct driveway length
20 Lost Swale Length From Trees,etc. 0 ft 0.0 ft3 Deduct other
21 Adjusted Length of Infiltration Area 88.0 ft
22 Excess Capacity=Storage-Deductions-Runoff Volume 599.6 ft3
23 Is Capacity Good? YES
24 Time to Drain 1,142.0 hr
90%volume in 48-hours minimum OK
https://wcgid.sharepoint.com/sites/WesternConsuItingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Des ign/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_LennonPt_Facility23-30.xlsm 4/6/2023,5:42 PM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 27
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 3,400
Acres 0.08
6 Determine the Weighted Runoff Coefficient(C) 0.75
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.75
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.15 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 202 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 126 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 20 ft' Concrete 0.95
Primary Treatment/StorageBasin V 182 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 202 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Permeable Interlocking Concrete Pavers (PICP)
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must
result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe Facility 27
Runoff Calculations
1 Design Storm 100 Link to: QV
2 Weighted Runoff Coefficient C 0.75 QV2
QV3
3 Area A(Acres) 0.08 acres Q,V4
0.00 cfs Q,VS
4 Approved Discharge Rate(if applicable) Q,v6�
5 Design Volume V 202 ft3 QV7
QV8
Paver&Aggregate Details
6 Enter Total Paver Area Length L 40.00 ft
7 Enter Total Paver Area Width W 12.00 ft
8 Total Paver Area A 480 ft2
9 Paver Joint Opening Area per Manf.Spec 0.10 Assume 0.10
10 Depth of Storage Stone 1.25 ft
11 Void Factor of Storage Stone(0.4 Max) 0.40
12 Available Storage in Paver Aggregate VAvaii 240 ft3
13 Does Aggregate Have Storage Capacity?Vavail V YES
Infiltration
14 Subgrade Infiltration Rate From Soils Report 0.48 in/hr
15 Time to Infiltrate -hrs Aggregate in/hr
16 Joint Aggregate Infiltration Rate:#8 Stone 500 in/hr #8 Stone 500.00
Peak Discharge
17 Time of Concentration Tc 10 min
18 Peak Q Qstorm 0.15 cfs
19 Capacity of Paver Joints QPeak_Pavers 0.56 cfs
20
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 27,750
Acres 0.64
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 1.15 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,541 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 963 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 154 ft' Concrete 0.95
Primary Treatment/StorageBasin V 1,387 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 1,541 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,9:23 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28Inlet W,100 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 8,490
Acres 0.19
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.35 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 472 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 295 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 47 ft' Concrete 0.95
Primary Treatment/StorageBasin V 424 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 472 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28Inlet W,25 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 8,490
Acres 0.19
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.25 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 339 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 295 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 34 ft' Concrete 0.95
Primary Treatment/StorageBasin V 305 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 339 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28 Inlet E,100 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 100
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 19,260
Acres 0.44
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 2.58 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.80 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 1,070 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 669 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 107 ft' Concrete 0.95
Primary Treatment/StorageBasin V 963 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 1,070 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Finding Peak Discharge/Volume-Rational Method
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the Engineer's calculation methodology. These
calculations shall establish a minimum requirement.The Engineer's methodology must result in facilities that meet or exceed these calculations in order to be accepted.
arge Rate�ational M�!Slated for
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28 Inlet E,25 year
2 Is area drainage basin map provided? YES
(map must be included with stormwater calculations)
3 Enter Design Storm(100-Year or 25-Year With 100-Year Flood Route) 25
Click to Show More Subbasins ❑
Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin Subbasin
1 Subbasin 2 3 4 5 6 7 8 9 10
5 Area of Drainage Subbasin(SF or Acres) SF 19,260
Acres 0.44
6 Determine the Weighted Runoff Coefficient(C) 0.70
C=[(C1xA1)+(C2xA2)+(CnxAn)]/A Weighted Avg1 0.70
7 Calculate Overland Flow Time of Concentration in Minutes(Tc)or use default 10 User Calculate
min 10 Min. Estimated Runoff Coefficients for Various Surface
- Type of Surface Runoff Coefficients N
8 Determine the average rainfall intensity(i)from IDF Curve based on Tc i 1.85 in/hr Business
Downtown areas 0.70-0.95
y Calculate the Post-Development peak discharge(QPeak) Qpe.k 0.57 cfs Urban neighborhoods 0.50-0.70
Residential
Single Family 0.35-0.50
10 Calculate total runoff vol(V)(for sizing primary storage) V 769 ft Multi-family 0.60-0.75
V=CI(Tc=60)Ax3600 Residential(rural) 0.25-0.40
11 Calculate Volume of Runoff Reduction Vrr Apartment Dwelling Areas 0.70
Industrial and Commercial
Enter Percentile Storm I(95th percentile=0.60 in) 95th 0.60 in Light areas 0.80
Enter Runoff Reduction Vol(95th Percentile=0.60-in x Area x C) Vrr 669 ft' Heavy areas 0.90
Parks,Cemeteries 0.10-0.25
12 Detention:Approved Discharge Rate to Surface Waters(if applicable) cfs Playgrounds 0.20-0.35
Railroad yard areas 0.20-0.40
13 Volume Summary Unimproved areas 0.10-0.30
Surface Storage:Basin Streets
Asphalt 0.95
Basin Forebay V 77 ft' Concrete 0.95
Primary Treatment/StorageBasin V 692 ft' Brick 0.95
Subsurface Storage Roofs 0.95
Gravel 0.75
Volume Without Sediment Factor(See BMP 20 Tab) V 769 ft' Fields:Sandy soil Soil Type
Slope A B C D
Flat:0-2% 0.04 0.07 0.11 0.
Average:2-6% 0.09 0.12 0.15 0.
Steep:>6% 0.13 0.18 0.23 0.
Adapted from ASCE
C:\Users\CarolineStanley\Desktop\ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/4/2023,11:45 AM
Version 10.5,November 2018
ACHD Calculation Sheet for Sizing Seepage Bed With Optional Chambers
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace the
Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's methodology must result
in facilities that meet or exceed these calculations in order to be accepted.
Note this spreadsheet pulls information from the"Peak Q,V"tab
Calculate Post-Development Flows(for pre-development flows,increase number of storage facilities to create new tab)
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28
2 Enter number of Seepage Beds(25 max) 3
3 Design Storm 100
4 Weighted Runoff Coefficient 0.70 Link to: 0V5
Qv6�
5 Area A(Acres) 0.64 acres [qv7
6 Approved discharge rate(if applicable) 0.00 cfs QVa
Q V9
7 Is Seepage Bed in Common Lot? Yes V 1,541 ft3 0%Sediment
8 Set Total Design Width of All Drain Rock W 9.0 ft
9 Set Total Design Depth of All Drain Rock D 4.5 ft
Rock Only,Do Not Include Filter Sand Depth or Cover
10 Void Ratio of Drain Rock Voids 0.4
0.4 for 1.5"-2"drain rock and 3/4"Chips
11 Design Infiltration Rate(8 in/hr max) Perc 0.65 in/hr
12 Size of WQ Perf Pipe(Perf 180°) Dia pipe 18 in
13 Size of Overflow Perf Pipe(Perfs 3600),READ if Q100>3.3 cfs in
14 Calculate Total Storage per Foot Spf 16.9 ft3/ft
15 Calculate Design Length L 91 62 ft
Override Value Required for Chambers
16 Variable Infiltration Window L SWL 62 ft
17 Variable Infiltration Window W SWW 9.0 ft
18 Time to Drain 45.9 hours
90%volume in 48-hours minimum
19 Length of WQ&Overflow Perf Pipes 62 ft
20 Perf Pipe Checks.Qperf>=Qpeak;
where Qperf-CdxAxV(2xgxH)
Optional Storage Chambers
Note:This assumes chambers are organized in a rectangular layout.
1-StormTech,
1 Type of Chambers SC740
2 Volume to Store V 496 ft3
3 Installed Chamber Width Cw 4.25 ft
Installed Chamber Depth Cd 2.50 ft
Installed Chamber Height Ch 7.12 ft
4 Chamber Void Factor
5 Chamber Storage Volume,Without Rock,Per Manuf 45.90 ft3/Unit
6 Chamber Storage Volume,With Rock,Per Manuf 74.90 ft3/Unit
7 Total Number of Units Required 7 7 ea
8 Area of Infiltration Aperc 275 ftZ
9 Volume Infiltration Vperc 15 ft3/hr
10 Time to Drain 29.9 hours
90%volume in 48-hours minimum
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final Design/Design/Calcs/Stormwater
Calcs/ACHD_SD_CALCS_LennonPt_Facility23-30.xlsm 4/9/2023,9:42 AM
Version 10.0,May 2018
ACHD Calculation Sheet for Sand/Grease Traps
NOTE:This worksheet is intended to be a guideline to standardize ACHD checking of drainage calculations and shall not replace
the Engineer's calculation methodology. These calculations shall establish a minimum requirement.The Engineer's
methodology must result in facilities that meet or exceed these calculations in order to be accepted.
User input in yellow cells.
1 Project Name Lennon Pointe Facility 28
2 Enter number of Sand/Grease Traps(25 max) 1
Number Peak Baffle Throat Velocity Is the
Vault Size of S/G Flow Q. Spacing width Area(ft) 0.5 fps Velocity
Traps cfs (inch) (inch) max. ok?
1000 G 1 1.15 11 48 3.67 0.31
Reference for Throat widths(inch)
ADS
Boise Lar-ken WQU,
Vault BMP 16
1000 G 48.0 50.5 n/a
1500 G 60.0 61.5 n/a
WQU1000 n/a n/a 60
WQU1500 n/a n/a 60
https://wcgid.sharepoint.com/sites/WesternConsultingGroupPLLC/Shared Documents/WCG/Projects/01-22-002 Lennon Pointe Final
Design/Design/Calcs/Stormwater Calcs/ACHD_SD_CALCS_Len non Pt_Facility23-30.xlsm 4/9/2023,9:38 AM
Version 10.0, May 2018
Hydraulic Analysis Report
Project Data
Project Title: Lennon Pointe Subdivision
Designer: CSN
Project Date: Monday,April 10, 2023
Project Units: U.S. Customary Units
Notes: Lennon Pointe Stormwater Pipe Sizing based on Manning's equation using FHWA
Hydraulic Tool Box software (Version 5.1.4.0,August 9, 2021)
Channel Analysis: Private Facility 1
Notes: 8"ADS dual wall HDPE pipe at 6.55%slope
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0655 ft/ft
Manning's n: 0.0120
Flow 0.7300 cfs
Result Parameters
Depth 0.2110 ft
Area of Flow 0.0951 ft^2
Wetted Perimeter 0.7983 ft
Hydraulic Radius 0.1192 ft
Average Velocity 7.6739 ft/s
Top Width 0.6224 ft
Froude Number: 3.4591
Critical Depth 0.4030 ft
Critical Velocity 3.2948 ft/s
Critical Slope: 0.0067 ft/ft
Critical Top Width 0.66 ft
Calculated Max Shear Stress 0.8623 lb/ft^2
Calculated Avg Shear Stress 0.4870 lb/ft^2
Channel Analysis: Private Facility 2
Notes: 8"C900 PCV pipe at 3.09%slope
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0309 ft/ft
Manning's n: 0.0120
Flow 1.6700 cfs
Result Parameters
Depth 0.4194 ft
Area of Flow 0.2322 ft^2
Wetted Perimeter 1.2231 ft
Hydraulic Radius 0.1899 ft
Average Velocity 7.1912 ft/s
Top Width 0.6484 ft
Froude Number: 2.1175
Critical Depth 0.5961 ft
Critical Velocity 5.0398 ft/s
Critical Slope: 0.0141 ft/ft
Critical Top Width 0.42 ft
Calculated Max Shear Stress 0.8087 lb/ft^2
Calculated Avg Shear Stress 0.3661 lb/ft^2
Channel Analysis: Private Facility 6 Inlet 1
Notes: West drop inlet, 8" C900 PVC pipe at 0.4%slope,calculations based on entire flow
discharge
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.3200 cfs
Result Parameters
Depth 0.2869 ft
Area of Flow 0.1442 ft^2
Wetted Perimeter 0.9560 ft
Hydraulic Radius 0.1508 ft
Average Velocity 2.2193 ft/s
Top Width 0.6631 ft
Froude Number: 0.8387
Critical Depth 0.2617 ft
Critical Velocity 2.5083 ft/s
Critical Slope: 0.0056 ft/ft
Critical Top Width 0.65 ft
Calculated Max Shear Stress 0.0716 lb/ft^2
Calculated Avg Shear Stress 0.0376 lb/ft^2
Channel Analysis: Private Facility 6 Inlet 2
Notes: East drop inlet, 8" C900 PVC pipe at 0.4%slope,calculations based on entire flow
discharge
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.3200 cfs
Result Parameters
Depth 0.2869 ft
Area of Flow 0.1442 ft^2
Wetted Perimeter 0.9560 ft
Hydraulic Radius 0.1508 ft
Average Velocity 2.2193 ft/s
Top Width 0.6631 ft
Froude Number: 0.8387
Critical Depth 0.2617 ft
Critical Velocity 2.5083 ft/s
Critical Slope: 0.0056 ft/ft
Critical Top Width 0.65 ft
Calculated Max Shear Stress 0.0716 lb/ft^2
Calculated Avg Shear Stress 0.0376 lb/ft^2
Channel Analysis: Private Facility 9
Notes: Drop inlet, 8" C900 PVC pipe at 0.4%slope, calculations based on entire flow
discharge
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.4100 cfs
Result Parameters
Depth 0.3305 ft
Area of Flow 0.1733 ft^2
Wetted Perimeter 1.0434 ft
Hydraulic Radius 0.1661 ft
Average Velocity 2.3663 ft/s
Top Width 0.6699 ft
Froude Number: 0.8200
Critical Depth 0.2980 ft
Critical Velocity 2.7051 ft/s
Critical Slope: 0.0057 ft/ft
Critical Top Width 0.67 ft
Calculated Max Shear Stress 0.0825 lb/ft^2
Calculated Avg Shear Stress 0.0414 lb/ft^2
Channel Analysis: PUBLIC Facility 11, Pipe 1
Notes: 12" HDPP pipe from West inlet at 0.4%slope,west inlet drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.3000 cfs
Result Parameters
Depth 0.2367 ft
Area of Flow 0.1422 ft^2
Wetted Perimeter 1.0163 ft
Hydraulic Radius 0.1399 ft
Average Velocity 2.1103 ft/s
Top Width 0.8502 ft
Froude Number: 0.9094
Critical Depth 0.2256 ft
Critical Velocity 2.2597 ft/s
Critical Slope: 0.0048 ft/ft
Critical Top Width 0.84 ft
Calculated Max Shear Stress 0.0591 lb/ft^2
Calculated Avg Shear Stress 0.0349 lb/ft^2
Channel Analysis: PUBLIC Facility 11, Pipe 2
Notes: 12" HDPP pipe between east inlet and concrete manhole at 0.4%slope,total basin
drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.9400 cfs
Result Parameters
Depth 0.4306 ft
Area of Flow 0.3235 ft^2
Wetted Perimeter 1.4315 ft
Hydraulic Radius 0.2260 ft
Average Velocity 2.9057 ft/s
Top Width 0.9903 ft
Froude Number: 0.8959
Critical Depth 0.4067 ft
Critical Velocity 3.1335 ft/s
Critical Slope: 0.0049 ft/ft
Critical Top Width 0.98 ft
Calculated Max Shear Stress 0.1075 lb/ft^2
Calculated Avg Shear Stress 0.0564 lb/ft^2
Channel Analysis: PUBLIC Facility 11, Pipe 3
Notes: 18" HDPP pipe between sediment manhole and sediment manhole at 2.2% slope,
total basin drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.50 ft
Longitudinal Slope: 0.0220 ft/ft
Manning's n: 0.0120
Flow 0.9400 cfs
Result Parameters
Depth 0.2403 ft
Area of Flow 0.1829 ft^2
Wetted Perimeter 1.2355 ft
Hydraulic Radius 0.1480 ft
Average Velocity 5.1398 ft/s
Top Width 1.1005 ft
Froude Number: 2.2219
Critical Depth 0.3611 ft
Critical Velocity 2.8701 ft/s
Critical Slope: 0.0042 ft/ft
Critical Top Width 1.28 ft
Calculated Max Shear Stress 0.3299 lb/ft^2
Calculated Avg Shear Stress 0.2032 lb/ft^2
Channel Analysis: PUBLIC Facility 22, Pipe 1
Notes: 12" HDPP pipe between east and west inlets at 0.4%slope,east inlet drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.2500 cfs
Result Parameters
Depth 0.2161 ft
Area of Flow 0.1249 ft^2
Wetted Perimeter 0.9670 ft
Hydraulic Radius 0.1292 ft
Average Velocity 2.0013 ft/s
Top Width 0.8232 ft
Froude Number: 0.9054
Critical Depth 0.2053 ft
Critical Velocity 2.1533 ft/s
Critical Slope: 0.0049 ft/ft
Critical Top Width 0.81 ft
Calculated Max Shear Stress 0.0539 lb/ft^2
Calculated Avg Shear Stress 0.0322 lb/ft^2
Channel Analysis: PUBLIC Facility 22, Pipe 2
Notes: 12" HDPP pipe between east inlet and sediment manhole at 0.4%slope,total basin
drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.9600 cfs
Result Parameters
Depth 0.4357 ft
Area of Flow 0.3285 ft^2
Wetted Perimeter 1.4418 ft
Hydraulic Radius 0.2279 ft
Average Velocity 2.9220 ft/s
Top Width 0.9917 ft
Froude Number: 0.8947
Critical Depth 0.4111 ft
Critical Velocity 3.1548 ft/s
Critical Slope: 0.0049 ft/ft
Critical Top Width 0.98 ft
Calculated Max Shear Stress 0.1087 lb/ft^2
Calculated Avg Shear Stress 0.0569 lb/ft^2
Channel Analysis: PUBLIC Facility 22, Pipe 3
Notes: 18" HDPP pipe between sediment manhole and seepage bed at 4.9%slope,total
basin drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.50 ft
Longitudinal Slope: 0.0490 ft/ft
Manning's n: 0.0120
Flow 0.9600 cfs
Result Parameters
Depth 0.2001 ft
Area of Flow 0.1401 ft^2
Wetted Perimeter 1.1215 ft
Hydraulic Radius 0.1249 ft
Average Velocity 6.8511 ft/s
Top Width 1.0199 ft
Froude Number: 3.2573
Critical Depth 0.3651 ft
Critical Velocity 2.8856 ft/s
Critical Slope: 0.0042 ft/ft
Critical Top Width 1.29 ft
Calculated Max Shear Stress 0.6117 lb/ft^2
Calculated Avg Shear Stress 0.3820 lb/ft^2
Channel Analysis: Private Facility 26, drainage area 26.1
Notes: 8" HDPP pipe at 0.4%slope,from north inlet
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.5900 cfs
Result Parameters
Depth 0.414 ft
Area of Flow 0.229 ft^2
Wetted Perimeter 1.213 ft
Hydraulic Radius 0.189 ft
Average Velocity 2.577 ft/s
Top Width 0.651 ft
Froude Number: 0.766
Critical Depth 0.361 ft
Critical Velocity 3.051 ft/s
Critical Slope: 0.0062 ft/ft
Critical Top Width 0.668 ft
Calculated Max Shear Stress 0.103 lb/ft^2
Calculated Avg Shear Stress 0.047 lb/ft^2
Channel Analysis: Facility 26.3, Pipe 1
Notes: 8"C900 pipe at 4.15% slope,between trench drain and sediment manhole
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0415 ft/ft
Manning's n: 0.0120
Flow 0.7000 cfs
Result Parameters
Depth 0.2326 ft
Area of Flow 0.1088 ft^2
Wetted Perimeter 0.8444 ft
Hydraulic Radius 0.1288 ft
Average Velocity 6.4347 ft/s
Top Width 0.6380 ft
Froude Number: 2.7461
Critical Depth 0.3942 ft
Critical Velocity 3.2445 ft/s
Critical Slope: 0.0066 ft/ft
Critical Top Width 0.66 ft
Calculated Max Shear Stress 0.6025 lb/ft^2
Calculated Avg Shear Stress 0.3336 lb/ft^2
Channel Analysis: Facility 26.3, Pipe 2
Notes: 8"C900 pipe at 1.17% slope,between sediment manhole and stormwater basin
Input Parameters
Channel Type: Circular
Pipe Diameter 0.67 ft
Longitudinal Slope: 0.0117 ft/ft
Manning's n: 0.0120
Flow 0.7000 cfs
Result Parameters
Depth 0.3302 ft
Area of Flow 0.1731 ft^2
Wetted Perimeter 1.0428 ft
Hydraulic Radius 0.1660 ft
Average Velocity 4.0448 ft/s
Top Width 0.6699 ft
Froude Number: 1.4025
Critical Depth 0.3942 ft
Critical Velocity 3.2445 ft/s
Critical Slope: 0.0066 ft/ft
Critical Top Width 0.66 ft
Calculated Max Shear Stress 0.2411 lb/ft^2
Calculated Avg Shear Stress 0.1212 lb/ft^2
Channel Analysis: PUBLIC Facility 28, Pipe 1
Notes: 12"HDPP pipe between east and west inlet at 0.4%slope, east inlet drainage area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 0.8000 cfs
Result Parameters
Depth 0.3940 ft
Area of Flow 0.2875 ft^2
Wetted Perimeter 1.3571 ft
Hydraulic Radius 0.2118 ft
Average Velocity 2.7830 ft/s
Top Width 0.9773 ft
Froude Number: 0.9043
Critical Depth 0.3740 ft
Critical Velocity 2.9843 ft/s
Critical Slope: 0.0048 ft/ft
Critical Top Width 0.97 ft
Calculated Max Shear Stress 0.0983 lb/ft^2
Calculated Avg Shear Stress 0.0529 lb/ft^2
Channel Analysis: PUBLIC Facility 28, Pipe 2
Notes: 12" HDPP pipe between west inlet and s&g trap at 0.4%slope, entire basin drainage
area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.00 ft
Longitudinal Slope: 0.0040 ft/ft
Manning's n: 0.0120
Flow 1.1500 cfs
Result Parameters
Depth 0.4829 ft
Area of Flow 0.3756 ft^2
Wetted Perimeter 1.5366 ft
Hydraulic Radius 0.2444 ft
Average Velocity 3.0617 ft/s
Top Width 0.9994 ft
Froude Number: 0.8801
Critical Depth 0.4517 ft
Critical Velocity 3.3388 ft/s
Critical Slope: 0.0051 ft/ft
Critical Top Width 1.00 ft
Calculated Max Shear Stress 0.1205 lb/ft^2
Calculated Avg Shear Stress 0.0610 lb/ft^2
Channel Analysis: PUBLIC Facility 28, Pipe 3
Notes: 18" HDPP pipe between s&g trap and seepage bed at 5.0%slope,total basin drainage
area
Input Parameters
Channel Type: Circular
Pipe Diameter 1.50 ft
Longitudinal Slope: 0.0500 ft/ft
Manning's n: 0.0120
Flow 1.1500 cfs
Result Parameters
Depth 0.2172 ft
Area of Flow 0.1579 ft^2
Wetted Perimeter 1.1711 ft
Hydraulic Radius 0.1349 ft
Average Velocity 7.2820 ft/s
Top Width 1.0557 ft
Froude Number: 3.3179
Critical Depth 0.4006 ft
Critical Velocity 3.0331 ft/s
Critical Slope: 0.0042 ft/ft
Critical Top Width 1.33 ft
Calculated Max Shear Stress 0.6777 lb/ft^2
Calculated Avg Shear Stress 0.4207 lb/ft^2
Lennon Pointe Subdivision
WESTERN CONSULTING
Stormwater Management Report G R O U P
Appendix 3
Geotechnical Report & Infiltration Recommendation
(under separate cover)
Page 12